Decentralized Application Architecture Flashcards
7 cards from real Blockchain Technology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Decentralized Application Architecture flashcards as text
In a typical dApp architecture, what is the primary role of the smart contract layer?
Answer: Encoding and enforcing the application's business logic and state transitions
Smart contracts hold the trustless business logic and on-chain state for a dApp.
Why do most dApps store large files on IPFS or Arweave rather than directly on-chain?
Answer: On-chain storage is extremely expensive per byte and bloats the chain
Storing bytes on-chain costs significant gas, so dApps store content off-chain and keep only the hash on-chain.
What does a 'content-addressed' storage system like IPFS use as a file identifier?
Answer: A cryptographic hash of the content (CID)
IPFS addresses content by a hash of its bytes, so the same content always yields the same CID.
Which component lets a browser-based dApp frontend submit transactions signed by the user?
Answer: A wallet provider injecting an Ethereum provider object
Wallets like MetaMask inject a provider that the frontend uses to request signatures and send transactions.
What is the main purpose of an indexing layer such as The Graph in a dApp stack?
Answer: To efficiently query and serve historical/aggregated on-chain data
Indexers transform raw chain events into queryable APIs since reading aggregated data directly from a node is slow.
In dApp architecture, what is a 'node provider' such as Infura or Alchemy responsible for?
Answer: Providing RPC access to blockchain nodes so apps avoid running their own
Node providers offer managed RPC endpoints so developers don't have to maintain full nodes.
Why is the frontend of most dApps still typically hosted on conventional or decentralized web hosting rather than on-chain?
Answer: Serving UI assets on-chain would be prohibitively expensive and slow
UI assets are served off-chain (e.g., IPFS/CDN) because on-chain hosting is costly and impractical.